1. Field of the Invention
There is a need for an inexpensive, easily installed low profile turntable which does not require extensive installation work. This invention has the advantage of only needing a flat surface area sufficient to accommodate the turntable itself, and a sufficiently flat surface to which the invention can be affixed. Vehicles or heavy loads can enter the turntable from any direction because the drive motors are inside the exterior ramps themselves. A concentric ring and perpendicular band construction called a “Spider” or “Spider System” allows precision installation with a minimum of work being required.
2. Description of Related Art
Historical attempts to address some or all of the limitations in prior patented machines have been numerous. Some examples of relevant art include:                U.S. Pat. No. 3,566,798, Mar. 2, 1971, Peitzman, United States (US) is an automobile turntable which must be installed flush with the surface where it is to be used. This requires excavation during the installation process.        U.S. Pat. No. 4,498,398, Feb. 12, 1985, Vallee, United States (US) The current invention construction is simpler and less complex than the Vallee invention.        U.S. Pat. No. 4,608,929, Sep. 2, 1986, Park, United States (US) requires a subsurface installation and therefore requires preparation and excavation of the surface it sits on.        U.S. Pat. No. 4,753,173, Jun. 28, 1988, James, United States (US) uses a cantilever design for strength on the platform, and spoke like members to support the upper deck of the turntable. while the current invention uses wedge shaped sections filled with structural foam giving greater strength and a more uniform upper surface, while decreasing installation complexity.        U.S. Pat. No. 4,777,884, Oct. 18, 1988, Seay, United States (US) must be installed below ground, a feature of installation avoided by the current invention.        U.S. Pat. No. 4,796,537, Jan. 10, 1993, Besser, United States (US) is a mobile truck turntable having a scow like body with a high vertical profile designed for portable use to move heavy trucks. The subject invention has the advantage of being portable, as well as being much lower to the ground with a lower profile.        U.S. Pat. No. 5,086,704, Feb. 11, 1992, Mueller, United States (US) uses a polygonal support frame, but still must be installed with a portion of itself below ground.        U.S. Pat. No. 5,090,508, Feb. 25, 1992, Nishikawa et. al., United States (US) is a turntable with a retractable lift. It is designed for repairing of automobiles and has extensive components as part of it's structure so that it can lift an automobile horizontally. The subject invention does not attempt to raise it's load vertically.        U.S. Pat. No. 5,538,357, Jul. 23, 2000, Boswell, United State (US) consists of a turntable requiring very powerful motors that can lift a vehicle vertically as well as rotate the turntable. The installation required extensive work in the area to be installed. The subject invention does not require as powerful motors since the drive mechanism only rotates a turntable in the horizontal axis. Only ⅓ horsepower motors are necessary for the current invention.        U.S. Pat. No. 5,626,079, May 6, 1997, Summers, United States (US) is a patent for an oscillating turntable for displaying vehicles. It differs from the subject invention because it consists of two vertical tiers of counter rotating turntables, lending to a complexity avoided by the subject invention.        U.S. Pat. No. 5,755,160, May 26, 1998, Blufordcraving, United States (US) is a rotating floor for automobiles but it also has similar disadvantages as the Summer U.S. Pat. No. 5,626,079. It must be installed below ground level, and it requires powerful motors to rotate it. The Subject invention sits on top of any flat ground surface, and the drive mechanism location is such that very little power is required to actually rotate the turntable.        U.S. Pat. No. 6,123,310, Jun. 19, 1998, Paskiewicz, United States (US) is a castor based platform for maneuvering and storing large numbers of motorcycles and other two wheeled vehicles.        U.S. Pat. No. 6,382,106, May 7, 2002, Knight, United States (US) uses tubular construction which makes the turntable high and necessitates a below ground construction.        U.S. Pat. No. 6,877,437, Apr. 12, 2005, Murdock, United States (US) also requires an underground installation which is not required by the subject invention.        